Olefin-based polymers are excellent in processability, chemical resistance, electrical properties, mechanical properties and the like, and thus, they are processed into extrusion molded articles, injection molded articles, blow molded articles, films, sheets and the like, to be provided for a wide variety of applications such as daily goods, kitchenware, packaging films, woven/non-woven fabrics, electric appliances, mechanical parts, electric parts, automobile parts and the like. In particular, olefin-based polymers containing 4-methyl-1-pentene are resins having excellent transparency, gas permeability and chemical resistance, as well as excellent thermal resistance, and thus, the polymers are widely used for medical instruments, thermally resistant wire coating, thermal resistant tableware and the like.
These olefin-based polymers are in general prepared using catalysts comprising transition metal compounds and organic aluminum compounds, that is, so-called Ziegler type catalysts. However, because the constitution of the polymers, such as molecular weight, is not uniformly obtained, the mechanical properties such as toughness and the like, and the strength of the polymers are deteriorated, and it has been requested to improve such properties in order for the olefin-based polymers to be used as products.
Meanwhile, those olefin-based polymers obtained using organometallic complex catalysts containing cyclopentadienyl groups, are in general characterized in that the constitution of the polymers, including molecular weight and the like, is uniform. However, it has been pointed out that the polymers are deteriorated in thermal resistance, compared with the conventional olefin-based polymers obtained with Ziegler type catalysts. As a possible cause for such deterioration, it is said that the olefin-based polymers prepared using conventional metallocene catalysts contain heterogeneous bonding between the monomer units to an extent of a few percent, and this adversely affects the polymer properties. Therefore, if olefin-based polymers having high thermal resistance as well as excellent processability and excellent impact resistance, thermal resistance, appearance, rigidity and tensile breaking elongation could be prepared, the industrial value thereof would be extremely great, and development of such olefin-based polymers is strongly demanded.
On the other hand, olefin-based elastomers, another family of olefin-based polymers, provide a material having excellent shock absorbability, heat sealability and the like, and thus are used individually, and also as a modifying agent for the aforementioned olefin-based polymers.
However, the conventional olefin-based elastomers not always have satisfactory thermal properties such as thermal resistance. Also, there has been a problem that their small molecular weights make the properties unsatisfactory. For this reason, if a novel olefin-based polymer having excellent thermal resistance as well as being excellently balanced in various properties as a result of increasing the molecular weight, could be prepared, the industrial value thereof would be extremely great, and development of such olefin-based polymers is strongly demanded.